Wave Trajectory and Electron Cyclotron Heating in Toroidal Plasmas

Wave trajectories propagating obliquely to magnetic field in toroidal plasmas are studied theoretically. Results show that the ordinary wave injected at appropriate incident angle can propagate into the dense plasmas and is mode-converted to the extraordinary wave at first turning point and is further converted to the electron Bernstein wave during passing a loop or a folded curve near second turning point and is cyclotron-damped away, resulting in local electron heating, before arriving at cyclotron resonance layer. Similar trajectory and damping are obtained when a microwave in a form of extraordinary wave is injected in the direction of decreasing toroidal field.